Bae Joohyun began her game wtih Kang Seulgi because the woman appeared so sweet and innocent. Bae Joohyun was the huntress and Kang Seulgi was her prey. Seulgi was the mouse, while she the cat, right? Bae Joohyun soon finds out the game wasn't as simple as she first thought, and perhaps it was her who was the mouse in this little game after all. 

Joohyun was the nice twin. She was the good twin that everyone loved and cared the most for. Leaving Irene with nothing and no one. Irene is sick and tired of playing second fiddle to her sister and plots her revenge. She'll steal that which Joohyun loves most of all, and that's her fiance Seulgi, after all Seulgi should have been hers in the first place, and Irene will take her back no mater what the costs.

It wasn't just Joohyun who Seulgi loved. Along with her wife, also came "Irene", a split personality who becomes a third person in their marriage. Seulgi knows that to love Joohyun is to love Irene too. This would be so much easier if Irene didn't hate her so, and could learn to love her too. Seulrene

Psychiatrist Bae Joohyun was hired to help reclusive, grieving famous artist Kang Seulgi come back to the real world. As she has been locked off from society for years. Only, no one told her that she had such a resemblance to her deceased wife, making the healing process that much more difficult. Seulrene.